1. Field of the Invention
The present invention relates to a vehicle air-conditioner conditioning the air inside a vehicle compartment.
2. Description of the Related Art
In the past, in automatic air-conditioning control of a vehicular air-conditioner, the inside/outside air intake mode, blowing port mode, and blower level have been controlled based on a target blowing temperature TAO so as to maintain the vehicle compartment temperature at a set temperature (for example, see Japanese Patent Publication (A) No. 2000-142077).
In this control, in air-conditioning in the winter, in particular at times of low outside air temperature, the outside air mode was used for the air-conditioning in order to prevent the front window glass from fogging up. Further, at the initial start of heating, the blowing port mode was set to the foot/defrost mode for a certain time in order to prevent the front window glass from fogging up.
However, along with the recent improvements in engine efficiency, the amount of heat given from the engine to the engine cooling water has been reduced and the engine cooling water no longer rises in temperature. For this reason, the heating capacity becomes insufficient. In particular, when heating in the outside air mode at the time of a low outside air temperature, the heating capacity will drop, the temperature inside the vehicle compartment will not rise, and passenger comfort will be impaired.
If setting the inside air mode, inside air is introduced, so the temperature of the introduced air can be raised compared with the outside air mode. For this reason, the temperature of the air inside the vehicle compartment can be raised faster. While the problem of the insufficient heating capacity can be eliminated, when setting the inside air mode, the humidity resulting from the respiration of the passengers causes the humidity in the vehicle compartment to immediately rise and ends up causing the front window glass to fog up.